The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

Photo: Yue Wu, The Chronicle

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The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

Photo: Yue Wu, The Chronicle

Image 3 of 5

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The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

The new PUC building at 525 Gold Gate Avenue claims to be one of the most "green" office buildings in the country on June 14, 2012, San Francisco, Calif.

Photo: Yue Wu, The Chronicle

Image 5 of 5

New PUC building - green, seems almost alive

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The headquarters of San Francisco's Public Utilities Commission was conceived in 2007 with aspirations to be the greenest office building in the urban United States.

As the sleek, 13-story box at 525 Golden Gate Ave. is readied for its Wednesday ribbon-cutting, reality falls short of the early grand vision. But the finished product still includes sustainable design features that push the norm and - most promising of all from an architectural standpoint - enliven the building's presence on the skyline and along the sidewalk.

You see this in the unusual landscaping along Polk Street that blurs the line between inside and out, and the horizontal blades of opaque glass that soften the appearance of the side of the building that faces City Hall. Above Golden Gate Avenue are the most expressive strokes of all: four egg-beater-like wind turbines on view behind a 200-foot-high, 22-foot-wide curtain of polycarbonate squares that ripple in the wind and, when the sun goes down, form a grid of flickering lights.

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The north-facing wall is clad in dark glass except for a thin band of white granite at each floor, with a rectangular form that folds in toward the tall stack of turbines and flares out above the corner entrance. The other facades have a more traditional look and increase the ratio of granite to glass, a nod to the Beaux Arts formalism of the Civic Center.

Closed since '89 quake

The corner was filled for decades by a squat state office building that never reopened after the 1989 Loma Prieta earthquake. Various city uses were reviewed before the commission stepped in and KMD Architects and Stevens Architects began design work on the $190.6 million, 277,500-square-foot building that will house 950 commission employees as well as a cafe and child care center.

But commission officials stress the educational side of what they bill as their "building for the future." One example is in the planters that frame the sidewalk and continue inside for several feet; they're designed to filter the building's wastewater as would a tidal wetland. The water then will be recycled for use in building toilets and urinals, one of the first "gray water" systems on a public building in the region.

The quartet of turbines is unusual as well.

While solar panels have become commonplace in the Bay Area, wind turbines on buildings remain a rarity. Here, though, KMD has shaped the tower to maximize the rush of winds along the facade and scoop it behind the wall that holds the rippling artwork. The turbines form a whirling stack, each rotating at a different pace.

Even with such innovations - and a hoped-for LEED Platinum ranking from the U.S. Green Building Council - 525 Golden Gate is a step in the right direction rather than the culmination of the journey toward environmentally spotless large buildings.

Shift in water usage

The most dramatic shift is in water usage. Between the gray water recycling and the storage of rainwater and wastewater in a 250,000-gallon subterranean tank, the building is expected to use 60 percent less water than office buildings of similar size.

The energy conservation target is 32 percent below standard office towers, while the turbines and 691 rooftop solar panels together will generate 7 percent of the building's energy needs. That's far less than the original target of generating 40 percent of the building's energy through turbines alone.

This isn't the first ultra-green building to fade as costs mounted and the allure for innovation was tempered by the desire for dependability. Gone are turbines on the roof, for instance, and embedded solar panels on the walls.

At the same time, the visible moves that were made reinforce the commission's efforts to encourage its customers - San Francisco residents and businesses - to find creative ways to conserve water and energy.

More than that, 525 Golden Gate demonstrates how sustainability efforts have a positive architectural effect.

By extending the sidewalk plantings that filter wastewater into the building, visible through the lobby's tall glass wall, the tower engages pedestrians in a way that most office buildings don't.

As for the horizontal fins of glass on the facade facing City Hall, they do more than block direct bright sunlight, instead deflecting it onto ceilings and adding natural light to the spaces. They also add a visual layer to the facade that's a precise contrast to the monolithic nature of other recent Civic Center buildings.

Best of all is the environmental sculpture "Firefly" by Sebastopol artist Ned Kahn.

The force of wind

The installation rises straight from the Golden Gate Avenue sidewalk, row upon row of 5-inch-square polycarbonate tiles intended "to show you the force of wind on the building," in Kahn's words. The area's strong gusts come in waves, making the wall rustle like a monochromatic LED display that never quite resolves into legible images.

It's as if the office block has an elusive presence all its own, lithe and alive. The churning turbines prod us to think about the connection between buildings and nature. The shimmering wall reminds us that buildings, like nature, can take on an unexpected beauty all their own.

More information on the environmental features of 525 Golden Gate Ave. are at www.sfwater.org/HQ